Removed clientID from NATS-Streaming Config (#6391)

clientID must be a unique `UUID` for each connections. Now, the
server generates it, rather considering the config.

Removing it as it is non-beneficial right now.

Fixes #6364

cmd/admin-handlers_test.go

@@ -38,7 +38,7 @@ import (
 
 var (
 	configJSON = []byte(`{
-  "version": "32",
+  "version": "33",
   "credential": {
     "accessKey": "minio",
     "secretKey": "minio123"
@@ -152,7 +152,6 @@ var (
         "streaming": {
           "enable": false,
           "clusterID": "",
-          "clientID": "",
           "async": false,
           "maxPubAcksInflight": 0
         }